Listen AudioConnect Series User manual

Listen, Inc. 580 Harrison Ave, Suite 3W, Boston, MA 02118
Tel: [phone] Fax: [phone] Web: www.listeninc.com
Sales: [email protected] Support: [email protected]
Listen, Inc. 580 Harrison Ave, Suite 3W, Boston, MA 02118
Tel: [phone] Fax: [phone] Web: www.listeninc.com
Sales: [e-mail] Support: [email protected]
AudioConnect
User Manual
TM
Listen, Inc. 580 Harrison Ave, Suite 3W, Boston, MA 02118. Tel: [phone].
Web: www.listeninc.com Sales: [email protected] Support: [email protected]
PN: 8090 REV 092016
AUDIOCONNECT USER MANUAL
© COPYRIGHT 2014-2016 LISTEN, INC.
PN: 8090 Rev 030519
AUDIOCONNECT USER MANUAL
© COPYRIGHT 2009-2019 LISTEN, INC.

Rev 030519

Contents
AudioConnectTM Manual i
Contents
Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .i
Limited Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iii
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Hardware Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Windows Mixer Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Headphone Amp Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
SoundCheck Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Auto Mode OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Back Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Recommended Cable Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Connection Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Loudspeaker Test using AudioConnectTM and SC AmpTM . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Balanced vs Single Ended Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Connect Series Hardware Shelf Mounting Instructions . . . . . . . . . . . . . . . . . . . . 15
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Equipment Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Declaration of Conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

ii Contents AudioConnectTM Manual
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Limited Warranty
AudioConnectTM Manual iii
Limited Warranty
LISTEN, Inc., a Massachusetts Corporation, having its principal place of business at 580 Harrison Ave,
Suite 3W, Boston, MA 02118 ("Manufacturer") warrants its AudioConnect products (the "Products") as
follows:
1. Limited Warranty.
Manufacturer warrants that the Products sold hereunder will be free from defects in material and
workmanship for a period of one (1) year from the date of purchase. If the Products do not conform to this
Limited Warranty during the warranty period (as herein above specified), Buyer shall notify Manufacturer in
writing of the claimed defects and demonstrate to Manufacturer satisfaction that said defects are covered
by this Limited Warranty. If the defects are properly reported to Manufacturer within the warranty period,
and the defects are of such type and nature as to be covered by this warranty, Manufacturer shall, at its own
expense, furnish, replacement Products or, at Manufacturer's option, replacement parts for the defective
Products. Shipping of the replacement Products or replacement parts shall be at Buyer's expense.
2. Other Limits.
THE FOREGOING IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE. Manufacturer does not warrant against damages or defects arising out of
improper or abnormal use of handling of the Products; against defects or damages arising from improper
installation (where installation is by persons other than Manufacturer), against defects in products or
components not manufactured by Manufacturer, or against damages resulting from such non-Manufacturer
made products or components. Manufacturer passes on to Buyer the warranty it received (if any) from the
maker thereof of such non-Manufacturer made products or components. This warranty also does not apply
to Products upon which repairs have been effected or attempted by persons other than pursuant to written
authorization by Manufacturer.
3. Exclusive Obligation.
THIS WARRANTY IS EXCLUSIVE. The sole and exclusive obligation of Manufacturer shall be to repair or
replace the defective Products in the manner and for the period provided above. Manufacturer shall not
have any other obligation with respect to the Products or any part thereof, whether based on contract, tort,
strict liability or otherwise. Under no circumstances, whether based on this Limited Warranty or otherwise,
shall Manufacturer be liable for incidental, special, or consequential damages.
4. Other Statements.
Manufacturer's employees or representatives' ORAL OR OTHER WRITTEN STATEMENTS DO NOT
CONSTITUTE WARRANTIES, shall not be relied upon by Buyer, and are not a part of the contract for sale
or this limited warranty.
5. Entire Obligation.
This Limited Warranty states the entire obligation of Manufacturer with respect to the Products. If any part of
this Limited Warranty is determined to be void or illegal, the remainder shall remain in full force and effect.

iv AudioConnectTM Manual
Limited Warranty
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Introduction
AudioConnectTM Manual 1
Introduction
The AudioConnectTM USB audio interface is designed to meet the majority of audio test and measurement
needs. It is specifically designed for audio and electroacoustic test and measurement. It offers two channels
of analog input and output as well as two channels of digital I/O, USB control, and a power indicator. All
other typical sound card controls that are not used for audio test applications have been eliminated. This
offers simple operation and calibration with no room for error. The interface is supplied fully calibrated.
Features
High quality professional audio interface
Analog audio in and out
2 Channels In / 2 Channels Out
USB Controlled in SoundCheck (AudioConnect requires SoundCheck 14 or later)
All other settings eliminated for ease of use
44.1 kHz sampling rate
SCM microphone power
Gain: 0 dB or 20 dB, front panel switchable. See Figure 1-1.
Headphone amplifier
Software Control Panel to allow easy switching of functions (AudioConnect requires SoundCheck
14 or later)
External USB hub
Internal USB hub: A secure place to keep the SoundCheck hardware key
Compact, rugged and rack-mountable
Excellent value
Figure 1-1: Front Panel
In Out
Figure 1-2: Back Panel

2AudioConnectTM Manual
Introduction
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Installation
AudioConnectTM Manual 3
Installation
Windows - AudioConnect uses a standard Windows WDM driver. Just connect to the SoundCheck
computer with the USB cable provided and the driver will install automatically.
Mac - AudioConnect uses a native Core Audio driver. The device is recognized after connecting with the
USB cable provided.
The AudioConnect Controller driver is included with the installation of SoundCheck 14 and later.
Important! SoundCheck 14 or later is required to control AudioConnect.
NI Visa
NI Visa is required for Listen Hardware such as: AmpConnect, AudioConnect and SoundConnect 2. It is
automatically installed with the SoundCheck installer for Windows and must be manually installed for Mac
OS.
Hardware Editor
Default values for the SoundCheck Hardware Editor are shown below.
Auto Mode
As of SoundCheck 14, the Hardware Editor in SoundCheck can automatically read the Vp values from
AudioConnect when the editor is set to Auto Mode. Please refer to the SoundCheck Manual Hardware
Editor chapter for more information on Auto Mode.
Important! The Output Channel Vp values read are for Balanced Connection. For Single
Ended (Unbalanced) Connections, uncheck Auto in the Hardware Editor.
Open the Hardware Editor from
the SoundCheck Main Screen.
Click Refresh to update
the Device Field. The
fields should now show
your device serial
number.
Balanced vs Single Ended
Vp Values
The example in Figure 2-1
shows the Output Vp value when
using Balanced Line, 1/4” Tip-
Ring-Sleeve (TRS) connectors.
The Vp value on Outputs 1 and 2
is 4.4 V.
Important! When using Single Ended connectors (1/4” Tip-Sleeve unbalanced), the
Output Vp values are reduced by half as shown in Figure 2-1, on Channel
Name - SnglEnd Out 1 and 2; e.g., [4.4 V / 2 = 2.2 V]
Figure 2-1: Balanced Output Values

4AudioConnectTM Manual
Installation
Windows Mixer Settings
Click on: Start > Control Panel > Hardware and Sound > Manage Audio Devices
Double click on AudioConnect under the Recording and Playback tabs.
The Windows audio mixer must be set to 100% for both Level and Balance as shown in Figure 2-2.
We also recommend that you set the mother board audio device (or an audio channel not used for
measurements) as the default Windows audio device as shown in Figure 2-3. This prevents Windows
sounds from playing back through AudioConnect.
Figure 2-2: Windows Mixer Settings
Figure 2-3: Set Default Device

Headphone Amp Calibration
AudioConnectTM Manual 5
Headphone Amp Calibration
When using the Headphone Out of AudioConnect for headphone testing, the Headphone Amp should be
calibrated in the SoundCheck Calibration editor.
Note: As of SoundCheck 14.01, the headphone out sensitivity is -5.8 dB (typical) when
using Balanced Out Vp values in the Hardware Editor. The calibrated sensitivity
of the Headphone Out is dependent on whether Balanced or Single Ended
connections and Vp values are used in the SoundCheck Hardware Editor. If you
change the Hardware Editor Output Vp values, the Headphone Amp must be re-
calibrated.
Note: As of SoundCheck 15, a new AudioConnect calibrated device is available in the
Calibration Editor. The output sensitivity is set to -5.8dB as a nominal value.
The following procedure allows you to calibrate the left and right
channels of the headphone amp. This will set the Sensitivity in the
Calibration editor and create a correction curve for both amp channels.
AudioConnect must be set to Line In before running the calibration
procedure. You can do this in the Hardware Editor - Listen Hardware -
Startup Defaults or from an Offline Message Step (select
AudioConnect.MES template). See Figure 3-1.
Set Channel 1 and 2 to Line
Set the Headphone Out to SoundCheck Output. The level is
fixed and cannot be adjusted in the editor.
Make sure Mute is not checked
Click Apply to send the settings to AudioConnect and OK to
exit the editor
This procedure requires the use of a Stereo 1/4” TRS to 1/4” Mono Left/Right cable typically called an Insert
Cable. The wiring is shown in Figure 3-2.
Figure 3-1: Message Step
In Out
L RStereo
Figure 3-2: Calibration Wiring

6AudioConnectTM Manual
Headphone Amp Calibration
Calibration Procedure
1. Open the Calibration Editor as shown in
Figure 3-3
2. In the Output Signal Path field select
Headphone Amp L (default name)
3. Under Calibrated Output Device, Click Add
and enter the name for the device:
AudioConnect Headphone Amp L.dat
4. Make sure the HW Output Channel is
correct. The default hardware channel is
Output 1.
5. Under Input Signal Path select the channel
that the output of the AudioConnect
Headphone Amp L is routed to.
6. Click Calibrate Device. When prompted
with wiring instructions, use the example in
Figure 3-2. Follow the sequence prompts,
clicking Enter to continue.
7. When the Amplifier Calibration process is
complete the display shows the response
curve of the headphone amp and the
measured gain. Click Enter to finish the
sequence. The gain value is automatically entered in the Sensitivity field as shown in Figure 3-3.
Select dBV to see the gain in dB.
8. Repeat the above procedure for the right headphone amp channel.
Figure 3-3: Calibration Editor

Operation
AudioConnectTM Manual 7
Operation
SoundCheck Control
AudioConnect can be controlled through the SoundCheck Hardware Startup Default or through message
steps. (SoundCheck 14 minimum required)
The default settings for AudioConnect can be set in
the SoundCheck Hardware Editor from the Listen
Hardware page. Right click on the AudioConnect
device line and select Assign Startup Default as
shown in Figure 4-1.
This allows you to use Auto Mode in the Hardware
Editor.
Auto Mode will set the appropriate Vp values for
the selected AudioConnect Input Channels.
Auto Mode OFF
Using Message Steps in a sequence to switch AudioConnect between Line In and Mic In will require that
Auto Mode is turned OFF in the Hardware Editor.
It also requires that discreet hardware input channels are created for Mic In 1 and 2 as well as
Line In 1 and 2. These channels should have the specific Vp values for each channel. These can be found
by using Auto Mode or from the AudioConnect QC Sheet. The values should be manually entered in the
Hardware Editor.
Settings
The Hardware Editor Startup Default and the AudioConnect Message Step settings panels are the same.
Open the AudioConnect Message Step in the sequence editor.
Listen Hardware is selected on the first page of the Message Editor
as shown in Figure 4-2.
Listen Hardware selected under Message
Pass/Fail - Not used in this type of step
Wait - Allows you to set a settling time so the Mic or Line
Inputs stabilize before a measurement is made
Click Configure Listen Hardware to open the device
settings panel (Figure 4-3)
Figure 4-1: Assign Startup Default
Figure 4-2: Message Step
Page 1

8AudioConnectTM Manual
Operation
Configure Listen Hardware
The Message Step for AudioConnect in Figure 4-3 shows the default
settings for AudioConnect.
Mic Bias
Turns the 9.5 VDC microphone bias On and Off for both
microphone input channels
Gain
Select 0 dB or +20 dB independently for channels 1 & 2
Input select
Select Mic or Line Input independently for channels 1 & 2
SoundCheck Hardware Editor Vp values automatically adjust
when AudioConnect input channels are switched between mic
and line via Message steps in a sequence
Output select
The output should be set to Line
Digital Out is currently not available.
Headphone
SoundCheck Output - Allows you to monitor the Output of the audio interface at the Headphone
jack. Use this setting if using the output for Headphone testing.
For use in headphone testing, the gain is fixed at 0.1 dB. The headphone out should be
calibrated in the SoundCheck Calibration Editor. The Headphone Amp Calibration Sequence
should be used. See Headphone Amp Calibration on page 5.
Note: Prior to serial number 40501270109, firmware 1.61, the headphone output polarity is inverted
for both channels. Polarity tests using the headphone out will need to be adjusted accordingly.
Polarity Limits may need to be changed from a Lower Limit of 0 to an Upper Limit of 0.
Input Monitor - Used to listen to the Input of the audio interface. Use this setting when verifying the
signal coming into SoundCheck.
Monitor level default is approx -16 dB
Apply - Click to send the current setting to the device
Read Settings - Click to get the current settings of the connected device
OK/Cancel - Click to close the device editor or message step
OK accepts the changes
Cancel will ignore the changes and return to the previously saved state
For more information on the use of Message Steps in a SoundCheck, please refer to the Message Editor
chapter of the SoundCheck Manual.
Analysis
AudioConnect requires that all Analysis Steps in SoundCheck sequences use Auto Delay on the Delay Tab.
Figure 4-3: Device Settings

Operation
AudioConnectTM Manual 9
Front Panel
Status LED
Off: No power has been applied to the
unit
Yellow: Power has been applied to the
unit, but there is no USB
communication with the computer
Green: Power has been applied to the
unit and there is USB communication
with the computer
Mic In
Microdot (10-32 female RF) connector
A constant voltage bias can be supplied for Listen, Inc. SCM Microphones as well as other
compatible electret-based measurement microphones.
Open Circuit Bias Voltage: 10 VDC
Bias voltage can be enabled for both inputs from the Message Step. See SoundCheck Control
on page 7.
Disable the Bias voltage when running the Sound Card calibration process on the microphone
inputs or when running Self Test.
LED Level Indicators
Off: Output level is less than -50 dBFS
Green: Output level is between -50 dBFS and -3 dBFS
Yellow: Output level is between -3 dBFS and 0 dBFS
Red: Output level has reached 0 dBFS
+20 dB Gain
Off: No gain applied. 0 dB
Green: +20 dB gain is applied
Applies to Mic In and Line In. Does not apply to Digital In.
Independently switchable on each channel
Headphone Out
Standard 1/4” TRS stereo headphone connection
See SoundCheck Control on page 7
Note: Prior to serial number 40501270109, firmware 1.61, the headphone output polarity is inverted
for both channels. Polarity tests using the headphone out will need to be adjusted accordingly.
Polarity Limits may need to be changed from a Lower Limit of 0 to an Upper Limit of 0.
Figure 4-4: Front Panel

Operation
AudioConnectTM Manual 10
Back Panel
Line In
1/4” Balanced TRS connector
Can also be used with Single Ended
connections
Line Out
1/4” Balanced TRS connector
Can also be used with Single Ended
connections
Note: Single Ended Output connections require a different Output Vp value in the SoundCheck
Hardware Editor. See Hardware Editor on page 3.
S/PDIF In/Out
Currently not available for use
USB device Connector
USB-B connector for connection to computer
USB Hub Connector
The USB Full Speed connector is for: Hardware Keys, keyboards, mice and control of devices such
as SoundConnect 2. It is not for use with hard drives, memory sticks or audio interfaces.
Internal USB Hub Connector
The USB Hub inside the case can be used for the SoundCheck USB Hardware Key
Note: Any steel cable or ball chain used to secure hardware keys and ID tags must be
removed before securing the hardware key in the AudioConnect chassis.
Power In Connector
24 VDC 0.5 A
Use only the approved DC supply provided by Listen, Inc.
Recommended Cable Length
All cables used for AudioConnect should be no longer than 3 meters (9.9 feet)
In Out
Figure 4-5: Back Panel

Operation
AudioConnectTM Manual 11
Connection Diagram
Loudspeaker Test using AudioConnectTM and SC AmpTM
AudioConnect connected to the SoundCheck computer via USB
SCM Microphone connected to Mic In 1 of AudioConnect
SoundCheck Message Step used to assign AudioConnect channel settings. See SoundCheck
Control on page 7.
AudioConnect Output 1 to SC Amp Line Input: Balanced connection recommended
SC Amp 0.1 V/A Impedance Interface Output to AudioConnect Input 2: Balanced connection
required (See Figure 4-6)
Loudspeaker connected to SC Amp Output
Reference
Microphone
-
+
501-4100-05-01
DC Voltage
Jumper Cable
AudioConnect
Back Panel
SC Amp Back Panel
1/4” Balanced TRS to TRS Cable
SoundCheck
Computer
USBUSB
Figure 4-6: Loudspeaker Test - Balanced Wiring

Operation
AudioConnectTM Manual 12
Balanced vs Single Ended Connections
AudioConnect accepts both Balanced and Single Ended (Unbalanced) connections.
BNC and RCA connections are both typically single ended.
As noted under Balanced vs Single Ended Vp Values on page 3, when a Single Ended Output
connection is used, the Vp value for that channel of the Hardware Editor should be half the value used for a
Balanced connection. The Input Vp values are not affected by single ended connections
Some instances may arise that require a single ended connection using a BNC or RCA connector. The
diagram in Figure 4-6 shows preferred wiring methods using these connectors.
Example 1
The common RCA to 1/4” Tip/Sleeve cable requires the use of Single Ended Vp values in the SoundCheck
Hardware Editor.
Example 2
This option allows you to still use Balanced Vp values in the Hardware Editor.
Example 3
While this method uses a 1/4” TRS connector, when the Ring is connected to the Sleeve it makes the
connection to AudioConnect Single Ended. This method requires the use of Single Ended Vp values in the
SoundCheck Hardware Editor.
Example 1: Common RCA to Tip/Sleeve Cable
Center Conductor to Tip
Center Conductor to Tip
Example 2: Modified RCA to Tip Ring Sleeve Cable
Example 3: Modified RCA to TRS Cable – Single Ended
+
Center Conductor to Tip
Shield to Sleeve
Sleeve Ring Tip
GND – +
Shield to Ring -
Sleeve is floating (NC)
+
Sleeve Ring Tip
GND – +
Shield to Sleeve -
Ring connected to Sleeve
+
This also applies to use with RCA/BNC adapters or
BNC custom cabling.
Sleeve Tip
GND +
Figure 4-7: Balanced vs Single Ended Wiring

Block Diagram
AudioConnectTM Manual 13
Block Diagram

14 AudioConnectTM Manual
Block Diagram
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